1 /*

     2  * Copyright 2007-2009 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any questions.

    24  */

    25 

    26 package java.nio.file;

    27 

    28 import java.nio.file.spi.FileSystemProvider;

    29 import java.net.URI;

    30 

    31 /**

    32  * This class consists exclusively of static methods that return a {@link Path}

    33  * by converting a path string or {@link URI}.

    34  *

    35  * @since 1.7

    36  */

    37 

    38 public class Paths {

    39     private Paths() { }

    40 

    41     /**

    42      * Constructs a {@code Path} by converting the given path string.

    43      *

    44      * <p> The {@code Path} is obtained by invoking the {@link FileSystem#getPath

    45      * getPath} method of the {@link FileSystems#getDefault default} {@link

    46      * FileSystem}.

    47      *

    48      * @param   path

    49      *          The path string to convert

    50      *

    51      * @return  The resulting {@code Path}

    52      *

    53      * @throws  InvalidPathException

    54      *          If the path string cannot be converted to a {@code Path}

    55      *

    56      * @see FileSystem#getPath

    57      */

    58     public static Path get(String path) {

    59         return FileSystems.getDefault().getPath(path);

    60     }

    61 

    62     /**

    63      * Converts the given URI to a {@link Path} object.

    64      *

    65      * <p> This method iterates over the {@link FileSystemProvider#installedProviders()

    66      * installed} providers to locate the provider that is identified by the

    67      * URI {@link URI#getScheme scheme} of the given URI. URI schemes are

    68      * compared without regard to case. If the provider is found then its {@link

    69      * FileSystemProvider#getPath getPath} method is invoked to convert the

    70      * URI.

    71      *

    72      * <p> In the case of the default provider, identified by the URI scheme

    73      * "file", the given URI has a non-empty path component, and undefined query

    74      * and fragment components. Whether the authority component may be present

    75      * is platform specific. The returned {@code Path} is associated with the

    76      * {@link FileSystems#getDefault default} file system.

    77      *

    78      * <p> The default provider provides a similar <em>round-trip</em> guarantee

    79      * to the {@link java.io.File} class. For a given {@code Path} <i>p</i> it

    80      * is guaranteed that

    81      * <blockquote><tt>

    82      * Paths.get(</tt><i>p</i><tt>.{@link Path#toUri() toUri}()).equals(</tt>

    83      * <i>p</i><tt>.{@link Path#toAbsolutePath() toAbsolutePath}())</tt>

    84      * </blockquote>

    85      * so long as the original {@code Path}, the {@code URI}, and the new {@code

    86      * Path} are all created in (possibly different invocations of) the same

    87      * Java virtual machine. Whether other providers make any guarantees is

    88      * provider specific and therefore unspecified.

    89      *

    90      * @param   uri

    91      *          The URI to convert

    92      *

    93      * @return  The resulting {@code Path}

    94      *

    95      * @throws  IllegalArgumentException

    96      *          If preconditions on the {@code uri} parameter do not hold. The

    97      *          format of the URI is provider specific.

    98      * @throws  FileSystemNotFoundException

    99      *          If the file system identified by the URI does not exist or the

   100      *          provider identified by the URI's scheme component is not installed

   101      * @throws  SecurityException

   102      *          If a security manager is installed and it denies an unspecified

   103      *          permission to access the file system

   104      */

   105     public static Path get(URI uri) {

   106         String scheme =  uri.getScheme();

   107         if (scheme == null)

   108             throw new IllegalArgumentException("Missing scheme");

   109 

   110         // check for default provider to avoid loading of installed providers

   111         if (scheme.equalsIgnoreCase("file"))

   112             return FileSystems.getDefault().provider().getPath(uri);

   113 

   114         // try to find provider

   115         for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {

   116             if (provider.getScheme().equalsIgnoreCase(scheme)) {

   117                 return provider.getPath(uri);

   118             }

   119         }

   120 

   121         throw new FileSystemNotFoundException("Provider \"" + scheme + "\" not installed");

   122     }

   123 }